Segmental cage for linear and linear/rotary bearings

ABSTRACT

A segmental cage for linear and linear-rotary bearings in which each of a plurality of identical cast cage segments comprises a body having cylindrical inner and outer surfaces and side edges lying in radial planes with an axially extending unloaded ball path-forming recess adjacent to one edge and with curved recesses adjacent its ends leading from the axial recess into an axially extending slot formed intermediate the segment edges with the slot adapted to receive a loading roller and so formed as to provide the loaded ball path and having a pair of axially spaced circumferentially extending lugs at the other edge adapted to extend into the curved recesses of an adjacent segment to define ball transfer paths for directing balls from the unloaded path to the loaded path.

United States Patent [1 1 Geffner SEGMENTAL CAGE FOR LINEAR ANDLINEAR/ROTARY BEARINGS Aug. 7, 1973 Primary ExaminerCharles J. MyhrcAssistant Examiner-Barry Grossman Attorney-Shenier & OConnor [57]ABSTRACT A segmental cage for linear and linear-rotary'bearings in whicheach of a plurality of identical cast cage segments comprises a bodyhaving cylindrical inner and outer surfaces and side edges lying inradial planes with an axially extending unloaded ball path-formingrecess adjacent to one edge and with curved recesses adjacent its endsleading from the axial recess into an axially extending slot formedintermediate the segment edges with the slot adapted to receive aloading roller and so formed as to provide the loaded ball path andhaving a pair of axially spaced circumferentially extending lugs at theother edge adapted to extend into the curved recesses of an adjacentsegment to define ball transfer paths for directing balls from theunloaded path to the loaded path.

11 Claims, 10 Drawing Figures PATENIEDAUB m 3.151.121

SHEET 2 [IF 2 INVENTOR.

H TTORNE Y5 SEGMENTAL CAGE FOR LINEAR AND LINEAR/ROTARY BEARINGSBACKGROUND OF THE INVENTION My copending application Ser. No. 28,719,now Pat. No. 3,692,371, discloses an improved anti-friction bearing, oneform of which is adapted to permit both rotary and axial relativemovement between a shaft and a housing or the like. The bearing shown inmy copending application includes a cage structure which is adapted toreceive rollers and balls so as to form ball paths comprising loadedball path portions extending axially and located between the shaft andthe rollers and unloaded ball path portions extending axially andlocated between the outer housing or sleeve and the cage structure. Theunloaded ball path portions are circumferentially spaced with respect tothe loaded ball path portions and are connected thereto by ball transferpath portions. Attempts were made to cast the retainer structure fromvarious synthetic resins. Such attempts, however, were not successful.The resultant retainer lacked dimensional stability. It was not asstrong as desirable. The frictional resistance to movement of the ballsalong the paths was excessive. The cost of producing the parts wasexcessive.

Other attempts were made to cast the retainer as a single piece from asuitable metal such as zinc. The cost of making the complicated dierequired to form the retainer was found to be prohibitive.'Even if themajor portion of the retainer were die cast from metal, a separate camelement had to be provided in order to form the transfer path portionsfor directing the balls between the loaded and unloaded ball pathportions.

I have invented a segmental cage for a combined linear and rotarybearing. My segmental cage may be cast at an overall cost which isappreciably less than the cost of casting a one piece retainer. Mysegmental cage does not require any separate cam element for forming thetransfer portions of the ball paths.

SUMMARY OF THE INVENTION One object of my invention is to provide asegmental ball cage for a combined linear and rotary bearing.

Another object of my invention is to provide a segmental cage for acombined linear and rotary hearing which can be cast from a relativelysimple die.

Yet another object of my invention is to provide a segmental cage for acombined linear and rotary bearing which can be cast at a lower costthan can a unitary cage of similar configuration.

Other and further objects of my invention will appear from the followingdescription.

In general, my invention contemplates the provision of a segmental cagefor a combined linear and rotary bearing in which each one of aplurality of cage segments-is an axially elongated arcuate body havingan axially extending unloaded ball path-forming recess adjacent one ofits edges and curved recesses adjacent its ends leading from the axialrecess into an axially extending slot intermediate the body edges andadapted to receive a loading roller or rollers and to form a loaded ballpath portion and having axially spaced circumferentially extending lugsor cam elements at its other edge for fitting into the curved recessesof an adjacent segment to complete the unloaded ball portion and theball transfer path portions extending between the loaded and theunloaded ball path portions.

BRIEF DESCRIPTION OF THE DRAWINGS In the accompanying drawings whichform part of the instant specification and which are to be read inconjunction therewith and in which like reference numerals are used toindicate like parts in the various views:

FIG. 1 is a side elevation of my segmental cage for combined linear androtary bearing showing the loading rollers and balls.

FIG. 2 is an end elevation of my segmental cage for a combined linearand rotary bearing.

FIG. 3 is a sectional view of my segmental cage for combined linear androtary bearing illustrating its relationship with the other parts of aninstallation with some parts removed.

FIG. 4 is a sectional view of the assembly shown in FIG. 3 taken alongthe line 44 of FIG. 3.

FIG. 5 is a top plan view of one segment of my segmental cage.

FIG. 6 is a sectional view of the segment shown in FIG. 5 taken alongthe line 66 of FIG. 5.

FIG. 7 is a bottom plan view of a segment of my segmental cage.

FIG. 8 is an end elevation of-a segment of my segmental cage.

FIG. 9 is a sectional view of my segmental cage taken along the line9--9 of FIG. 5 and drawn on an enlarged scale.

FIG. 10 is a sectional view of a portion of a segment of mysegmentalcage taken along the line I0-I0 of FIG. 5.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to FIGS. 1 to 4 ofthe drawings, a combined linear and rotary bearing indicated generallyby the reference character 10 may include an outer sleeve or housing 12,a shaft 14, and my segmental cage indicated generally by the referencecharacter 16. As will more fully be pointed out hereinbelow, the cage 16provides a plurality of loaded ball path portions 18 and a plurality ofunloaded ball path portions 20. Connecting path portions 22 adjacent theends of the cage 16 connect the ends of the loaded path portions to theends of the unloaded path portions 20. Loading rollers 24 locatedbetween the loaded path portions and the outer housing 12 so positionthe balls 26 as to be in load bearing relationship with the rollers 24and the shaft 14. I provide the rollers 24 with tapered ends 28 whichare engaged by the balls 26 as they move through the curved end portionsto rotate rollers 24.

The structure thus far described with the exception of the segmentalnature of the cage 16, is the same as that described in my copendingapplication referred to hereinabove. The operation of the structure isset forth in detail in the copending application.

Referring now to FIGS. 5 to 10, the segmental cage 16 is made up of aplurality of identical segments, each of which is indicated generally bythe reference character 30. As will further be pointed out hereinbelowin the particular embodiment of my cage shown in the drawings, eightsegments 30 are required to make up a complete cage. I die cast each ofthe segments 30 from a suitable material such, for example, as zinc oraluminum or the like. Each segment 30 has an inner cylindrical surface32 and an outer cylindrical surface 34, as

well as respective circumferentially spaced sides 36 and 38 lying inradial planes.

I form each of the segments 30 with an axially extending recess 40adjacent to and leading into the edge 36. The depth of the recess 40 inthe radial direction is somewhat greater than half the thickness of thesegment 30 so that the recess or groove 40 is adapted to form unloadedpath portions in a manner to be described.

I provide each of the segments with respective curved recess portions 42and 44 adjacent the ends thereof, which portions lead from the ends ofthe groove into respective curved end portions 46 and 48 of an axialslot 50 located in the segment 30 intermediate the edges 36 and 38. Itwill be appreciated that the curved recess portions gradually deepen asthey progress from the axially extending recess or groove 40 into curvedend portions 46 and 48 of an axially extending slot 50 formed in thesegment intermediate the sides 36 and 38. The cross sectional shape ofthe slot 46 is such as to form retaining lips 52 and 54 adjacent to theinner surface 32 of the segment 30.

I provide each of the segments 30 with a pair of axially spacedcircumferentially extending cams or lugs 56 and 58 along the edge 38.The dimensions of lugs 56 and 58 are such that the lugs of one segmentfit into the curved path portion of an adjacent segment and the edge 38of the first segment abuts the edge 36 of the adjacent segment tocomplete the unloaded ball path portions 20. Moreover, I form each ofthe lugs with a generally triangular cross sectional shape as shown inFIG. 10 so that the lugs complete the transfer path portions 22 in thefinished assembly. Each of the lugs 56 and 58 has an axial width whichis slightly less than the width of groove 40.

In use of my segmental retainer 16 I first assemble a number of mysegments 30 to form a complete annulus with the lugs 56 and 58 of oneretainer extending into the adjacent segment 30 at locations at whichthey overlie the curved path portions 42 and 44. As this is done theside edges 36 and 38 are brought into abutting relationship. In theparticular configuration shown I provide a cage or retainer 16 which ismade up of eight segments. It will readily be appreciated that a greateror lesser number of segments may be required where more or less ballpaths are to be provided.

After the segments have been assembled in a suitable fixture they areretained therein and the balls 26 and rollers 24 are assembled in theretainer. As this assembly is removed from the fixture a sleeve such assleeve 12 is applied thereto and the bearing is ready for installation.

It will readily be apparent from the configuration of my retainersegments 30 illustrated in the drawings that a die for framing thesegment is appreciably less complex than a die which would be requiredto form a unitary retainer. Having made the die, a plurality of retainersegments can be cast from any suitable material such as zinc or aluminumor the like.

It will be seen that I have accomplished the objects of my invention. Ihave provided a segmental retainer for a combined axial and rotarybearing. My segmental retainer can be die cast at an overall cost whichis appreciably less than the cost of casting a unitary retainer ofsimilar configuration. My segmental retainer does not require anyseparate transfer path cam member. While I have shown rollers withtapered ends, it is to be understood that, if desired, I could use endswith different configurations, such as squared ends. The retainers aredescribed as being made of suitable metal, such as zinc. The zinccastings can be chrome or nickel-plated, if desired. The retainersfurthermore can be made sufficiently thick to accommodate two rollerssuch as is shown in my copending application, above identified.

It will be understood that certain features and subcombinations are ofutility and may be employed without reference to other features andsubcombinations. This is contemplated by and is within the scope of myclaims. It is further obvious that various changes may be made indetails within the scope of my claims without departing from the spiritof my invention. It is, therefore, to be understood that my invention isnot to be limited to the specific details shown and described.

Having thus described my invention, what I claim is:

I claim:

1. A segmental cage for a bearing including in combination, a pluralityof integral axially elongated arcuate segments adapted to be juxtaposedto form an axially elongated annulus, each of said segments being formedwith a generally axially extending slot with curved slot portions at theends of said slot, each of said segments being formed with a generallyaxially extending recess circumferentially spaced from the segment slotwith curved inwardly extending recess portions at the ends of saidrecess leading into said curved slot portions and means for positioningadjacent segments to cause said slots to form loaded ball path portionsand said recesses to form unloaded ball path portions andto cause saidcurved slot and recess portions to form ball transfer path portions.

2. A segmental cage as in claim 1 in which each of said segments hadradially directed axially extending edges, said recess being formedadjacent to and leading into one of said edges, the other edge of anadjacent segment cooperating with said one edge to form said unloadedball path portion.

3. A segmental cage as in claim 1 in which each of said segments has acylindrical inner surface and means forming a retaining lip along theedge of said slot adjacent said inner surface.

4. A segmental cage as in claim 1 in which said juxtapositioning meanscomprises axially spaced circumferentially extending lugs on the edge ofone segment extending into the adjacent segment over said curved recessportions.

5. A segmental cage as in claim 4 in which each of said lugs is formedwith a generally triangular cross section providing a surface formingpart of said transfer path portions.

6. A segmental cage as in claim 1 in which each of said segments is aunitary metal member.

7. A segmental cage for a bearing including in combination, a pluralityof axially elongated segments each having a cylindrical inner surfaceand a cylindrical outer surface and side edges lying in radial planes,each of said segments being formed with a generally axially extendingslot intermediate the side edges with curved end slot portions directedtoward one of said side edges, each of said segments being formed with agenerally axially extending recess in said outer surface adjacent to andleading into said one side edge, curved and inwardly directed recessportions directed toward the other side edge and extending into saidcurved slot portions, and axially spaced lugs extendingcircumferentially from the other side edge, the lugs of one segmentadapted to extend into the curved recess portions of an adjacent segmentto position said segments so that said slots form loaded ball pathportions and said recesses form unloaded ball path portions and saidlugs and curved slots and recess portions form ball transfer pathportions.

8. A segmental cage as in claim 7 in which said one edge of one segmentabuts the other edge of an adjacent segment to form said unloaded ballpath portion.

9. A segmental cage as in claim 7 in which each of said lugs has agenerally triangular cross sectional shape to provide a portion of thesurface of said ball transfer path portions.

10. A segmental cage as in claim 7 in which each segment comprises aretaining lip along the edge of said slot adjacent to said innersurface.

11. In a segmental cage, a unitary cage segment comprising an axiallyelongated unitary body having cylindrical inner and outer surfaces andhaving side edges lying in radial planes, means forming a generallyaxially extending slot in said body with curved end slotportions'directed toward one of said edges, means forming a generallyaxially extending groove in said outer surface adjacent to and leadinginto one of said sides with curved and radially inwardly extending endgroove por tions leading into said curved slot portions andcircumferentially extending spaced lugs each having generally triangularcross sectional shape on the other side, said lugs registering generallywith the junctures of said curved groove and slot portions, said lugshaving an axial width slightly less than that of said groove.

1. A segmental cage for a bearing including in combination, a pluralityof integral axially elongated arcuate segments adapted to be juxtaposedto form an axially elongated annulus, each of said segments being formedwith a generally axially extending slot with curved slot portions at theends of said slot, each of said segments being formed with a generallyaxially extending recess circumferentially spaced from the segment slotwith curved inwardly extending recess portions at the ends of saidrecess leading into said curved slot portions and means for positioningadjacent segments to cause said slots to form loaded ball path portionsand said recesses to form unloaded ball path portions and to cause saidcurved slot and recess portions to form ball transfer path portions. 2.A segmental cage as in claim 1 in which each of said segments hadradially directed axially extending edges, said recess being formedadjacent to and leading into one of said edges, the other edge of anadjacent segment cooperating with said one edge to form said unloadedball path portion.
 3. A segmental cage as in claim 1 in which each ofsaid segments has a cylindrical inner surface and means forming aretaining lip along the edge of said slot adjacent said inner surface.4. A segmental cage as in claim 1 in which said juxtapositioning meanscomprises axially spaced circumferentially extending lugs on the edge ofone segment extending into the adjacent segment over said curved recessportions.
 5. A segmental cage as in claim 4 in which each of said lugsis formed with a generally triangular cross section providing a surfaceforming part of said transfer path portions.
 6. A segmental cage as inclaim 1 in which each of said segments is a unitary metal member.
 7. Asegmental cage for a bearing including in combination, a plurality ofaxially elongated segments each having a cylindrical inner surface and acylindrical outer surface and side edges lying in radial planes, each ofsaid segments being formed with a generally axially extending slotintermediate the side edges with curved end slot portions directedtoward one of said side edges, each of said segments being formed with agenerally axially extending recess in said outer surface adjacent to andleading into said one side edge, curved and inwardly directed recessportions directed toward the other side edge and extending into saidcurved slot portions, and axially spaced lugs extendingcircumferentially from the other side edge, the lugs of one segmentadapted to extend into the curved recess portions of an adjacent segmentto position said segments so that said slots form loaded ball pathportions and said recesses form unloaded ball path portions and saidlugs and curved slots and recess portions form ball transfer pathportions.
 8. A segmental cage as in claim 7 in which said one edge ofone segment abuts the other edge of an adjacent segment to form saidunloaded ball path portion.
 9. A segmental cage as in claim 7 in whicheach of said lugs has a generally triangular cross sectional shape toprovide a portion of the surface of said ball transfer path portions.10. A segmental cage as in claim 7 in which each segment comprises aretaining lip along the edge of said slot adjacent to said innersurface.
 11. In a segmental cage, a unitary cage segment comprising anaxially elongated unitary body having cylindrical inner and outersurfaces and having side edges lying in radial planes, means forming agenerally axially extending slot in said body with curved end slotportions directed toward one of said edges, means forming a generallyaxially extending groove in said outer surface adjacent to and leadinginto one of said sides with curved and radially inwardly extending endgroove portions leading into said curved slot portions andcircumferentially extending spaced lugs each having generally triangUlarcross sectional shape on the other side, said lugs registering generallywith the junctures of said curved groove and slot portions, said lugshaving an axial width slightly less than that of said groove.